Switch to blocking IO model for reading output from processes

src/GitHub.Api/NewTaskSystem/ProcessTask.cs

@@ -56,7 +56,6 @@ class ProcessWrapper
         private readonly Action onEnd;
         private readonly Action<Exception, string> onError;
         private readonly CancellationToken token;
-        private readonly List<string> errors = new List<string>();
 
         public Process Process { get; }
         public StreamWriter Input { get; private set; }
@@ -78,39 +77,6 @@ public ProcessWrapper(Process process, IOutputProcessor outputProcessor,
 
         public void Run()
         {
-            if (Process.StartInfo.RedirectStandardOutput)
-            {
-                Process.OutputDataReceived += (s, e) =>
-                {
-                    //Logger.Trace("OutputData \"" + (e.Data == null ? "'null'" : e.Data) + "\"");
-
-                    string encodedData = null;
-                    if (e.Data != null)
-                    {
-                        encodedData = Encoding.UTF8.GetString(Encoding.Default.GetBytes(e.Data));
-                    }
-                    outputProcessor.LineReceived(encodedData);
-                };
-            }
-
-            if (Process.StartInfo.RedirectStandardError)
-            {
-                Process.ErrorDataReceived += (s, e) =>
-                {
-                    //if (e.Data != null)
-                    //{
-                    //    Logger.Trace("ErrorData \"" + (e.Data == null ? "'null'" : e.Data) + "\"");
-                    //}
-
-                    string encodedData = null;
-                    if (e.Data != null)
-                    {
-                        encodedData = Encoding.UTF8.GetString(Encoding.Default.GetBytes(e.Data));
-                        errors.Add(encodedData);
-                    }
-                };
-            }
-
             try
             {
                 Process.Start();
@@ -133,34 +99,65 @@ public void Run()
                 return;
             }
 
-            if (Process.StartInfo.RedirectStandardOutput)
-                Process.BeginOutputReadLine();
-            if (Process.StartInfo.RedirectStandardError)
-                Process.BeginErrorReadLine();
             if (Process.StartInfo.RedirectStandardInput)
                 Input = new StreamWriter(Process.StandardInput.BaseStream, new UTF8Encoding(false));
 
-            onStart?.Invoke();
+            var errors = new List<string>();
 
+            onStart?.Invoke();
             if (Process.StartInfo.CreateNoWindow)
             {
-                while (!WaitForExit(500))
+                if (Process.StartInfo.RedirectStandardOutput)
                 {
-                    if (token.IsCancellationRequested)
+                    var outputStream = Process.StandardOutput;
+                    var line = outputStream.ReadLine();
+                    while (line != null)
                     {
-                        if (!Process.HasExited)
-                            Process.Kill();
-                        Process.Close();
-                        onEnd?.Invoke();
-                        token.ThrowIfCancellationRequested();
+                        outputProcessor.LineReceived(line);
+
+                        if (token.IsCancellationRequested)
+                        {
+                            if (!Process.HasExited)
+                                Process.Kill();
+
+                            Process.Close();
+                            onEnd?.Invoke();
+                            token.ThrowIfCancellationRequested();
+                        }
+
+                        line = outputStream.ReadLine();
                     }
+                    outputProcessor.LineReceived(null);
                 }
 
-                if (Process.ExitCode != 0 && errors.Count > 0)
+                if (Process.StartInfo.RedirectStandardError)
                 {
-                    onError?.Invoke(null, String.Join(Environment.NewLine, errors.ToArray()));
+                    var errorStream = Process.StandardError;
+                    var errorLine = errorStream.ReadLine();
+                    while (errorLine != null)
+                    {
+                        errors.Add(errorLine);
+
+                        if (token.IsCancellationRequested)
+                        {
+                            if (!Process.HasExited)
+                                Process.Kill();
+
+                            Process.Close();
+                            onEnd?.Invoke();
+                            token.ThrowIfCancellationRequested();
+                        }
+
+                        errorLine = errorStream.ReadLine();
+                    }
+
+                    if (Process.ExitCode != 0 && errors.Count > 0)
+                    {
+                        onError?.Invoke(null, string.Join(Environment.NewLine, errors.ToArray()));
+                    }
                 }
             }
+
             onEnd?.Invoke();
         }